Protective helmets having hard outer shells for use in various military, industrial or other applications are well known in the art. In such helmets, it is generally desirable to provide a resilient liner assembly between the outer shell and the wearer's head to help absorb shock. While straps or similar elements have customarily been used in the past for this purpose, they must be adjustable to accommodate various head sizes, resulting in some wobbling from front to back or from side to side.
Various proposals for individually fitted, or form-fitting, liner assemblies have been suggested in an attempt to overcome this defect. Such proposals involve, for example, making an individual mold of the wearer's head or, as disclosed in U.S. Pat. No. 3,882,546, forming the liner in place by injecting foam between the outer shell and thin cap stretched over the wearer's head. While these and other proposals have met with some degree of success, they are expensive and time-consuming and are not readily adaptable for use with various helmet shell designs. More importantly, methods of the prior art for custom fitting helmets are not practicable for use in the field. Further, the broad area of contact of the completed helmet assembly with the wearer's head can result in some discomfort, particularly in closed areas, by preventing free circulation of air.